Device for automatically preventing motor vehicles from rolling back on grades



July 3, 1945. A. .1. RUSSELL ,379,

DEVICE FOR AUTOMATICALLY PREVENTING MOTOR VEHICLES FROM ROLLING BACK ON GRADES Flled June 14 1944 2 Sheets-Sheet 1 INVENTOR. #:3227- Jffzussm July 3, 1945 A. J. RUSSELL DEVICE FOR AUTOMATICALLY PREVENTING MOTOR VEHICLES FROM ROLLING BACKON GRADES ,Filed June 14, 1944 2 Sheets-Sheet 2 I 'mmvronh. I

- reverse position. v

. ON. GRADES.

This invention aims to provide means for motor vehicles whereby, when the car is facing up hill and atrest, and is about to be started forward,

the car will be automatically restrained from 'rolling backward, so th at'it'may be safely started fore" ward up the. hill *with the elimination of thecommon-dangerof first descending a distance before it canebe started forward. The nuisance menn .j 3 i DEVICE-Eon AUTOMATICALLY PREVENTINGM I ......=..MOTOR.VEHICLES FROMUROLLINGLBACKJ Alb rt-J. RuSSeILNeW YorIgf N. I k n .l Application June.14, 1944,.Seriali No... ,540,180.'

' tonne-elf nema FJZ tioned is a very common one and causes af considerabl amount of annoyance to drivers,=-'as a special skill is generally necessary for the driver to avoid the down roll of the car priorto getting i't imderway. "Anotherobject of'this invention is the provision of the means above mentioned in conjunctionwithmeans fordeactivising the first-named means automatically upon Shifting of the gear shift leverinto reverse positionin order to enable the car to be backed up, and conversely automatically "reactivising the first-named means upon disengagement of theshift lever fromthe The-above and'other objects will become apparent in the description below, wherein characters of reference refer to like-numbered parts in the accompanying drawings. It is to be. noted that the drawings are intended for the purpose of illustration only, and it is neither intended nor desired to limit the invention necessarily to the exact details shown excepting insofar as'they may be deemed essential to the invention.

Referring briefly to the drawings, Fig. 1 is a fragmentary plan view, partly in section, of the transmission of a motor vehicle, showing the invention applied thereto. Fig. 2 is a perspective view of the membersof housing Ill and one end thereof is provided with i i. low .ilttf in slots ll which passthrough I the .ring; in such mannerr-zthat the rollers although: confinedi late: erally within the slots are free. to .movel a: short distance radially with respect to: l the v drums I It;

The ring I5 and its rollers I6 areebuiltcinl ac cordance with standard. freerwheeling principles;

' .T-he ring l5 is-confmed on thedrum flll bymeans or boltedagainst of anannular washer I8 screwed the side of the drum. i

wTheperipheral surface of the drum III-isigouged out or otherwise formed to provide aseries of' identical zig-zag like peripheral cam surfaces I9 whichywith -the radialwvall 20 at oneiend'of each. surface or floor 2I of thecams I9, constituteray series =of' pockets arranged around i the periphery.

The floor 2| of each cam I9 rises from the base of its wallZIl to thepeakof the wa1l20 of the next adjacent pocket. 'Thus', each pocket has ;a depth which is at the maximum at one end, at the wall2fli and which gradually les'sens to zero at theother end, at the next wall 20. I The member 22 comprises a body 25 having a' flange 23 extending forward therefroin and. "a collar or flange 24 on the rear end thereof, and this member is keyed to the shaft II with-"the flange 23 registering around the ring I5 and roller I6, as shown in Fig. ,1. When thus assembled, the rollers I6 are in light contactwith the inner surface of the flange 23.

A stub shaft 26 is pivotally mounted inthe a toothed arm or hook 21 adapted to register in one of the slots I3 of the wheel I2. Inside the housing III the shaft 26 has a bent arm 28. A

the device, with one member separated from the others. i Fig. 3 is a sectional view taken of Fig. 1. n

Fig. 4 isa sectional view taken on the line 4-4 of Fig. 1.

Fig. 5 is a sectional View taken on the line 5-5 on the line 33 of Fig. 1.

Referring in detail to the drawings, the nu-,

meral II] indicates the transmission case or housing of a motor vehicle and II the transmission or drive shaft extending rearward (toward the left Fig. 1) toward the differential, not shown. Loosely mounted on the shaft II is a toothed.

, wheel I2 having slots I3 between the teeth thereof. Integral-with and extending rearward from the wheel I2 is a flange or drum I4. Loosely mounted on the drum I4 is a ring I5 having a plurality of spaced rollers I6 mounted therein,

coiled spring29 having one end anchored inthe housing I0 and the other extending over the top of the arm 28, normally urges the hook 21 into engagement with the wheel I2. A rod 30 is slidably mounted in the housing I0, and the arm 28 rests thereagainst. An upwardly sloping ramp orcam 3| isrigid on the arm 30 near the forward end thereof, and when the rod is moved rearward the cam 3| forces the-arm 28 upward and thereby disengages the hook 21 from the wheel I2 and permits the latter to rotate on the shaft II. Either the fork of the gear shift lever or an extension thereof, shown at 32, partly en-' circles the shaft, so while the lever is being shifted into reverse gear so as to simultaneously shift the rod 30 rearward, and when the lever is moved out of reverse gearthe rod 30 will be withdrawn to its inactive position, thus permitting. the spring 29 to push the hook 21 into engagement with. the wheel I2.

As the hook 21 normally registers in a slot I3, '1

1 shaft II.

practicallyfrictionless contact with the rollers, through the medium-of afilm of oil v As soon as the shaft n begins to turn in the direction of, the arrow, as, for instance, when the vehicle is facspirit and scope of the invention.

I claim: I

1. In combination with the transmission shaft of a motor vehicle, a toothed wheel loosely mounted on said shaft, a drum integral with said wheel, a cylindrical member keyed on said shaft and'having a flange {surrounding-said drum,

, v,said drum and said member for interlocking said:

ing uphill and the clutch is disengaged preparatory to starting forward, the engagement of the 3 I rpllers I6 with the inner surface ofthe fiange'23 if is sufficient for the latter to move the rollers (and the ring [5) also in the same direction, and in doing so the rollers instantly lock with the flange 23 and thereby lock the shafts against rotation, so that the vehicle is thus prevented fromrolling backward down hill.

5 When it is desired to, back up the car, however, shiftingthe gear :lever 32 into reverse gear, as above, setiforth, disengages the hook 21 fromtthe,

wheel :;I 2 so that, the latter is then free i to. rotate and hencedoes-not obstruct rotation of the shaft ll 'in the reverse direction.

I .practice,, the rollers 16 are of course :well coatedwith oil, andaheavy oil. The entire device including the membersfIZ-A and 22 may be mounted otherwise or elsewhere than illustrated and described, ifor instance, entirely within the transmission housing III, in which case the entire device would be. wellbathed in the transmission ;The;;same.funotioning could be achieved with other means. For instance, if the drum M were made integral with the wheel I2 and keyed tothe shaft I l, and themember 22 were loosely positioned on the shaft II with the flange 23 en-. circling the ringylE, the device would function on'the principle of centrifugal force acting upon the rollers it. Or pawls could be substituted for the; rollers in -the latter construction,

means partly on said drum and partlybetween "drum and said member upon rotation of" said shaft in one direction and for disengagingsaid i interlocking upon rotation of said shaft in the reverse direction, and releasable means normally ,locking. said. toothed wheel against rotation.

2. The device set forth in claim Lsaid releasable means comprising a hook having means normally urging the same against said toothed wheel, and means for disengaging said hook from said toothed wheel. Q a

The device set forth inclaim 1, said releasable means, comprising a rod rotatably mounted parallel withsaid shaft, said rod haVing, a hook thereon adjacent said wheel, resilient means normally urging said hook into engagement with" said wheel, and mean forrotatingsaid rod I to lift said hook out of,engagementwitnsaid wheel. 4. The vdevice set forth parallel with said first shaft, said stubshaft;hav,.

ing a hook thereon and having means for nor-m mally urging rotation thereof in a direction toengage said hook with said WheeLsaidstub shaft having an arm, thereon, a rod slidably mounted parallel with said stub shaft and .having said ALBERT J; RUCSASELL;

Obviously, modifications in form and struc-. ture may be made without departing fromthe in claim l leasable means comprising a stub shaft mounted 

